In Hero Sex Academia, the vast majority of humans have experienced a strange gene with multiple mutations. The gene causes them to develop special abilities and characteristics. Now the world is filled with superhumans who have to use their powers to save others, and they're referred to as Superheroes. The protagonist is the son of the most powerful hero, and he disappeared several years ago without a trace. Now he must attend the Heroes Academy. What he learns there will change the course of his life and will give him the avenge his father and return peace to the world.